1. Field of the Invention
The present invention relates to disk drives for computer systems. More particularly, the present invention relates to a disk drive employing a configuration data structure comprising a plurality of configuration parameters to facilitate disk commands.
2. Description of the Prior Art
Prior art disk drives have employed global parameters to configure various aspects of the disk drive to facilitate disk commands such as read/write commands. For example, during a calibration procedure the disk drive may be configured to write test data at an offset from the target track's centerline in order to decrease the signal-to-noise ratio (SNR) during read-back, thereby expediting the calibration process. A global tracking offset parameter is configured to select the desired head offset for the write operation during the calibration procedure. This creates a problem, however, if the global tracking offset parameter is not re-configured after the write operation, or if subsequent write operations fail to configure the global tracking offset parameter to an appropriate value. Accordingly, a subsequent normal write operation may assume the tracking offset is zero, fail to configure the global tracking offset parameter, and end up writing user data with an undesirable tracking offset. This problem is exacerbated when the functionality of the disk drive is expanded by creating new global parameters which requires rewriting existing code to achieve forward compatibility and writing new code to achieve backward compatibility.